removal of pyrophosphate from the 5' end of mRNAs to make RNA accessible for degradation by [SW|RNases] [Pubmed|21925382]

RppH requires at least two unpaired nucleotides at the 5' end of its RNA substrates and prefers three or more. The second of these 5'-terminal nucleotides must be G, whereas a less strict preference for a purine is evident at the third position, and A is slightly favored over G at the first position [Pubmed|23610425,23610407]